Question

m/2+n/3=13 m/3-n/4=3 用代入法做

方程组 m/2+n/3=13 m/3-n/4=3 用代入法做

Answer 1

m + 2n/3 = 26
m = 26 - 2n/3
(26 - 2n/3)/3 - n/4 = 3
26 - 2n/3 - 3n/4 = 9
-2n/3 - 3n/4 = -17
2n/3 + 3n/4 = 17
n (2/3 + 3/4) = 17
n = 12
m = 26 - 2*12/3 = 18

Answer 2

m=2(13-n/3)
代入
(26-2n/3)/3-n/4=3
26/3-2n/9-n/4=3
-n(2/9+1/4)=3-26/3
-n=36/17*(3-26/3)
-n=108/17-312/17
n=204/17
n=12
m=2(13-12/3)
m=18

Answer 3

n(2/3+3/4)=17
n=12
m=26-2*12/3=18
m=18

Answer 4

m=18,n=12